Why Does My Internet Keep Dropping Offline on My Mac?

Before you look to the Mac itself for causes of a dropped Internet signal, check for environmental factors that might be to blame. If you have devices in your building that emit wireless signals, such as garage-door openers, cordless phones or remote sprinkler controls, the signals may be interfering with your Wi-Fi network. If the Internet signal stays steady when you disable all other wireless devices, interference is probably to blame. Change the frequency on your router; your Mac will adjust itself automatically.

The position of your router can affect the signal. When the router is too far away from the computer or has a weak antenna, the signal can drop unexpectedly. Thick walls and metal objects such as refrigerators and radiators can also interfere with the signal. For optimal performance, place your router in a central location, away from walls, floors and metal objects. If you cannot move the router, a Wi-Fi repeater or range booster can reduce or eliminate dropped connections. Other solutions include upgrading your router's firmware and replacing the antenna with a high-gain model.

The easiest way to solve a dropping Internet connection in the short term is to turn the router connection off; wait a few minutes and turn it back on. Also, close your computer, restart it or put it to sleep. If the problem occurs only occasionally, the router may be to blame; power-cycle the router by unplugging all the cables and cords and reconnecting them after a few minutes to reset the network. If the Internet connection drops out frequently and does not respond to basic troubleshooting, change the system preferences.

Your Mac has a list of preferences that guide the way it connects to the Internet. In the Network section of the System Preferences panel, you can change the network port configurations. The existing settings vary by computer. To optimize them for your connection, click and drag the port configuration to set the order your computer connects to a network. If you are connecting via Wi-Fi, place the router at the top of the list; if you use an Ethernet cable, drag that option to the top. If you don't use any of the listed configurations, unselect them. To cement the settings, reset your Mac's PRAM by restarting while holding down the "Command," "Option," "P" and "R" keys simultaneously.